Originally Published: 26 MAY 21 10:42 ET

By Jason Hanna and Omar Jimenez, CNN

(CNN) -- Darnella Frazier says she still struggles with what she witnessed a year after recording the murder of George Floyd.

Frazier, then 17, was on her way to a Minneapolis store to buy snacks with her young cousin when she captured the clearest video of police officer Derek Chauvin pressing his knee into Floyd's neck.

On Tuesday -- a year to the day after Floyd's death -- she reflected on the weight that she's carried since that moment.

"It changed me. It changed how I view life. It made me realize how dangerous it is to be Black in America," Frazier posted on Facebook on Tuesday afternoon.

Now 18, she said she still feels "the weight and trauma of what I witnessed a year ago."

"It's a little easier now, but I'm not who I used to be. A part of my childhood was taken from me. ... Having to up and leave because my home was no longer safe, waking up to reporters at my door, closing my eyes at night only to see a man who is brown like me, lifeless on the ground."

Frazier's video of Floyd's final moments was widely credited for helping secure a guilty verdict against Chauvin, and Minnesota Gov. Tim Walz publicly thanked her after the trial.

"Taking that video, I think many folks know, is maybe the only reason that Derek Chauvin will go to prison," Walz said last month.

Frazier wrote Tuesday that "behind the publicity, I'm a girl trying to heal from something I am reminded of every day."

She wrote she didn't know Floyd "from a can of paint, but I knew his life mattered."

"I knew that he was in pain," Frazier wrote. "I knew that he was another Black man in danger with no power."

She wrote that though people call her a hero, "I don't see myself as one," and that "I was just in the right place at the right time."

"George Floyd, I cant express enough how I wish things could have went different, but I want you to know you will always be in my heart," she wrote. "I'll always remember this day because of you. May your soul rest in peace."